According to (()) section 9.2, responses to OPTIONS requests may contain response bodies:

"A 200 response SHOULD include any header fields that indicate optional features implemented by the server and applicable to that resource (e.g., Allow), possibly including extensions not defined by this specification. The response body, if any, SHOULD also include information about the communication options."

As it currently stands, net/http is not useful for issuing an OPTIONS request to an http server which actually makes use of the response body.